kubelet

package
v0.4.1 Latest Latest
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 Go to latest Published: Mar 9, 2015 License: Apache-2.0 Imports: 45 Imported by: 0

Documentation

Overview

Package kubelet is the package that contains the libraries that drive the Kubelet binary. The kubelet is responsible for node level pod management. It runs on each worker in the cluster.

Index

Constants

View Source 
const (
	RunOnceManifestDelay     = 1 * time.Second
	RunOnceMaxRetries        = 10
	RunOnceRetryDelay        = 1 * time.Second
	RunOnceRetryDelayBackoff = 2
)
View Source 
const (
	// This is the current pod configuration
	SET PodOperation = iota
	// Pods with the given ids are new to this source
	ADD
	// Pods with the given ids have been removed from this source
	REMOVE
	// Pods with the given ids have been updated in this source
	UPDATE

	// These constants identify the sources of pods
	// Updates from a file
	FileSource = "file"
	// Updates from etcd
	EtcdSource = "etcd"
	// Updates from querying a web page
	HTTPSource = "http"
	// Updates received to the kubelet server
	ServerSource = "server"
	// Updates from Kubernetes API Server
	ApiserverSource = "api"
	// Updates from all sources
	AllSource = "*"
)
View Source 
const ConfigSourceAnnotationKey = "kubernetes.io/config.source"
View Source 
const (
	PodInfraContainerImage = "kubernetes/pause:latest"
)

Variables

View Source 
var (
	// ErrNoKubeletContainers returned when there are not containers managed by the kubelet (ie: either no containers on the node, or none that the kubelet cares about).
	ErrNoKubeletContainers = errors.New("no containers managed by kubelet")

	// ErrContainerNotFound returned when a container in the given pod with the given container name was not found, amongst those managed by the kubelet.
	ErrContainerNotFound = errors.New("no matching container")

	// ErrCadvisorApiFailure returned when cadvisor couldn't retrieve stats for the given container, either because it isn't running or it was confused by the request
	ErrCadvisorApiFailure = errors.New("failed to retrieve cadvisor stats")
)

Functions

func EtcdClientOrDie added in v0.2.1 

func EtcdClientOrDie(etcdServerList util.StringList, etcdConfigFile string) tools.EtcdClient

TODO: move this into a pkg/tools/etcd_tools

func GetPodFullName 

func GetPodFullName(pod *api.BoundPod) string

GetPodFullName returns a name that uniquely identifies a pod across all config sources.

func ListenAndServeKubeletServer 

func ListenAndServeKubeletServer(host HostInterface, address net.IP, port uint, enableDebuggingHandlers bool)

ListenAndServeKubeletServer initializes a server to respond to HTTP network requests on the Kubelet.

func MonitorCAdvisor added in v0.2.1 

func MonitorCAdvisor(k *Kubelet, cp uint)

TODO: move this into the kubelet itself

func ParsePodFullName added in v0.2.1 

func ParsePodFullName(podFullName string) (podName, podNamespace string, podAnnotations map[string]string)

ParsePodFullName unpacks a pod full name and returns the pod name, namespace, and annotations. If the pod full name is invalid, empty strings are returend.

func ResolvePort 

func ResolvePort(portReference util.IntOrString, container *api.Container) (int, error)

ResolvePort attempts to turn a IntOrString port reference into a concrete port number. If portReference has an int value, it is treated as a literal, and simply returns that value. If portReference is a string, an attempt is first made to parse it as an integer. If that fails, an attempt is made to find a port with the same name in the container spec. If a port with the same name is found, it's ContainerPort value is returned. If no matching port is found, an error is returned.

func SetupCapabilities added in v0.2.1 

func SetupCapabilities(allowPrivileged bool)

TODO: move this into pkg/capabilities

func SetupEventSending added in v0.2.1 

func SetupEventSending(client *client.Client, hostname string)

func SetupLogging added in v0.2.1 

func SetupLogging()

TODO: Split this up?

Types

type ByCreated added in v0.2.1 

type ByCreated []*docker.Container

func (ByCreated) Len added in v0.2.1 

func (a ByCreated) Len() int

func (ByCreated) Less added in v0.2.1 

func (a ByCreated) Less(i, j int) bool

func (ByCreated) Swap added in v0.2.1 

func (a ByCreated) Swap(i, j int)

type FlushWriter 

type FlushWriter struct {
	// contains filtered or unexported fields
}

FlushWriter provides wrapper for responseWriter with HTTP streaming capabilities

func (*FlushWriter) Write 

func (fw *FlushWriter) Write(p []byte) (n int, err error)

Write is a FlushWriter implementation of the io.Writer that sends any buffered data to the client.

type HostInterface 

type HostInterface interface {
	GetContainerInfo(podFullName string, uid types.UID, containerName string, req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
	GetRootInfo(req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
	GetDockerVersion() ([]uint, error)
	GetMachineInfo() (*info.MachineInfo, error)
	GetBoundPods() ([]api.BoundPod, error)
	GetPodByName(namespace, name string) (*api.BoundPod, bool)
	GetPodStatus(name string, uid types.UID) (api.PodStatus, error)
	RunInContainer(name string, uid types.UID, container string, cmd []string) ([]byte, error)
	ExecInContainer(name string, uid types.UID, container string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool) error
	GetKubeletContainerLogs(podFullName, containerName, tail string, follow bool, stdout, stderr io.Writer) error
	ServeLogs(w http.ResponseWriter, req *http.Request)
	PortForward(name string, uid types.UID, port uint16, stream io.ReadWriteCloser) error
	StreamingConnectionIdleTimeout() time.Duration
}

HostInterface contains all the kubelet methods required by the server. For testablitiy.

type Kubelet 

type Kubelet struct {
	// contains filtered or unexported fields
}

Kubelet is the main kubelet implementation.

func NewMainKubelet 

func NewMainKubelet(
	hostname string,
	dockerClient dockertools.DockerInterface,
	etcdClient tools.EtcdClient,
	kubeClient *client.Client,
	rootDirectory string,
	podInfraContainerImage string,
	resyncInterval time.Duration,
	pullQPS float32,
	pullBurst int,
	minimumGCAge time.Duration,
	maxContainerCount int,
	sourceReady SourceReadyFn,
	clusterDomain string,
	clusterDNS net.IP,
	masterServiceNamespace string,
	volumePlugins []volume.Plugin,
	streamingConnectionIdleTimeout time.Duration) (*Kubelet, error)

New creates a new Kubelet for use in main

func (*Kubelet) BirthCry added in v0.2.1 

func (kl *Kubelet) BirthCry()

BirthCry sends an event that the kubelet has started up.

func (*Kubelet) ExecInContainer added in v0.4.1 

func (kl *Kubelet) ExecInContainer(podFullName string, uid types.UID, container string, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error

ExecInContainer executes a command in a container, connecting the supplied stdin/stdout/stderr to the command's IO streams.

func (*Kubelet) GarbageCollectContainers added in v0.2.1 

func (kl *Kubelet) GarbageCollectContainers() error

TODO: Also enforce a maximum total number of containers.

func (*Kubelet) GarbageCollectLoop added in v0.2.1 

func (kl *Kubelet) GarbageCollectLoop()

func (*Kubelet) GetBoundPods added in v0.2.1 

func (kl *Kubelet) GetBoundPods() ([]api.BoundPod, error)

GetBoundPods returns all pods bound to the kubelet and their spec

func (*Kubelet) GetCadvisorClient 

func (kl *Kubelet) GetCadvisorClient() cadvisorInterface

GetCadvisorClient gets the cadvisor client.

func (*Kubelet) GetContainerInfo 

func (kl *Kubelet) GetContainerInfo(podFullName string, uid types.UID, containerName string, req *cadvisor.ContainerInfoRequest) (*cadvisor.ContainerInfo, error)

GetContainerInfo returns stats (from Cadvisor) for a container.

func (*Kubelet) GetDockerVersion added in v0.3.2 

func (kl *Kubelet) GetDockerVersion() ([]uint, error)

Returns Docker version for this Kubelet.

func (*Kubelet) GetKubeletContainerLogs 

func (kl *Kubelet) GetKubeletContainerLogs(podFullName, containerName, tail string, follow bool, stdout, stderr io.Writer) error

GetKubeletContainerLogs returns logs from the container The second parameter of GetPodStatus and FindPodContainer methods represents pod UUID, which is allowed to be blank TODO: this method is returning logs of random container attempts, when it should be returning the most recent attempt or all of them.

func (*Kubelet) GetMachineInfo 

func (kl *Kubelet) GetMachineInfo() (*cadvisor.MachineInfo, error)

func (*Kubelet) GetPodByName added in v0.2.1 

func (kl *Kubelet) GetPodByName(namespace, name string) (*api.BoundPod, bool)

GetPodFullName provides the first pod that matches namespace and name, or false if no such pod can be found.

func (*Kubelet) GetPodStatus added in v0.2.2 

func (kl *Kubelet) GetPodStatus(podFullName string, uid types.UID) (api.PodStatus, error)

GetPodStatus returns information from Docker about the containers in a pod

func (*Kubelet) GetRootInfo 

func (kl *Kubelet) GetRootInfo(req *cadvisor.ContainerInfoRequest) (*cadvisor.ContainerInfo, error)

GetRootInfo returns stats (from Cadvisor) of current machine (root container).

func (*Kubelet) PortForward added in v0.4.1 

func (kl *Kubelet) PortForward(podFullName string, uid types.UID, port uint16, stream io.ReadWriteCloser) error

PortForward connects to the pod's port and copies data between the port and the stream.

func (*Kubelet) Run 

func (kl *Kubelet) Run(updates <-chan PodUpdate)

Run starts the kubelet reacting to config updates

func (*Kubelet) RunInContainer 

func (kl *Kubelet) RunInContainer(podFullName string, uid types.UID, container string, cmd []string) ([]byte, error)

Run a command in a container, returns the combined stdout, stderr as an array of bytes

func (*Kubelet) RunOnce 

func (kl *Kubelet) RunOnce(updates <-chan PodUpdate) ([]RunPodResult, error)

RunOnce polls from one configuration update and run the associated pods.

func (*Kubelet) ServeLogs 

func (kl *Kubelet) ServeLogs(w http.ResponseWriter, req *http.Request)

Returns logs of current machine.

func (*Kubelet) SetCadvisorClient 

func (kl *Kubelet) SetCadvisorClient(c cadvisorInterface)

SetCadvisorClient sets the cadvisor client in a thread-safe way.

func (*Kubelet) StreamingConnectionIdleTimeout added in v0.4.1 

func (kl *Kubelet) StreamingConnectionIdleTimeout() time.Duration

func (*Kubelet) SyncPods 

func (kl *Kubelet) SyncPods(pods []api.BoundPod) error

SyncPods synchronizes the configured list of pods (desired state) with the host current state.

type PodOperation 

type PodOperation int

PodOperation defines what changes will be made on a pod configuration.

type PodUpdate 

type PodUpdate struct {
	Pods   []api.BoundPod
	Op     PodOperation
	Source string
}

PodUpdate defines an operation sent on the channel. You can add or remove single services by sending an array of size one and Op == ADD|REMOVE (with REMOVE, only the ID is required). For setting the state of the system to a given state for this source configuration, set Pods as desired and Op to SET, which will reset the system state to that specified in this operation for this source channel. To remove all pods, set Pods to empty object and Op to SET.

Additionally, Pods should never be nil - it should always point to an empty slice. While functionally similar, this helps our unit tests properly check that the correct PodUpdates are generated.

type RunPodResult 

type RunPodResult struct {
	Pod *api.BoundPod
	Err error
}

type Server 

type Server struct {
	// contains filtered or unexported fields
}

Server is a http.Handler which exposes kubelet functionality over HTTP.

func NewServer 

func NewServer(host HostInterface, enableDebuggingHandlers bool) Server

NewServer initializes and configures a kubelet.Server object to handle HTTP requests.

func (*Server) InstallDebuggingHandlers 

func (s *Server) InstallDebuggingHandlers()

InstallDeguggingHandlers registers the HTTP request patterns that serve logs or run commands/containers

func (*Server) InstallDefaultHandlers 

func (s *Server) InstallDefaultHandlers()

InstallDefaultHandlers registers the default set of supported HTTP request patterns with the mux.

func (*Server) ServeHTTP 

func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request)

ServeHTTP responds to HTTP requests on the Kubelet.

type SourceReadyFn added in v0.2.1 

type SourceReadyFn func(source string) bool

type SyncHandler 

type SyncHandler interface {
	SyncPods([]api.BoundPod) error
}

SyncHandler is an interface implemented by Kubelet, for testability

Source Files

View all Source files

Directories

Path Synopsis
Reads the pod configuration from the Kubernetes apiserver.
 Reads the pod configuration from the Kubernetes apiserver.
Package envvars is the package that build the environment variables that kubernetes provides to the containers run by it.
 Package envvars is the package that build the environment variables that kubernetes provides to the containers run by it.
Package leaky holds bits of kubelet that should be internal but have leaked out through bad abstractions.
 Package leaky holds bits of kubelet that should be internal but have leaked out through bad abstractions.
Package volume includes internal representations of external volume types as well as utility methods required to mount/unmount volumes to kubelets.
 Package volume includes internal representations of external volume types as well as utility methods required to mount/unmount volumes to kubelets.
empty_dir
gce_pd
git_repo
host_path
secret

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